Deprecate the online flake registries and vendor the default registry

Fixes #183, #110, #116.

The default flake-registry option becomes 'vendored', and refers
to a vendored flake-registry.json file in the install path.

Vendored copy of the flake-registry is from github:NixOS/flake-registry
at commit 9c69f7bd2363e71fe5cd7f608113290c7614dcdd.

Change-Id: I752b81c85ebeaab4e582ac01c239d69d65580f37

3 files changed, 75 insertions, 0 deletions

diff --git a/tests/functional/flakes/flake-registry.sh b/tests/functional/flakes/flake-registry.sh
new file mode 100644
index 000000000..73ab353bf
--- /dev/null
+++ b/tests/functional/flakes/flake-registry.sh
@@ -0,0 +1,72 @@
+source ./common.sh
+
+# remove the flake registry from nix.conf, to set to default ("vendored")
+sed -i '/flake-registry/d' "$NIX_CONF_DIR/nix.conf"
+
+# Make sure the vendored registry contains the correct amount.
+[[ $(nix registry list | wc -l) == 37 ]]
+# sanity check, contains the important ones
+nix registry list | grep '^global flake:nixpkgs'
+nix registry list | grep '^global flake:home-manager'
+
+
+# it should work the same if we set to vendored directly.
+echo 'flake-registry = vendored' >> "$NIX_CONF_DIR/nix.conf"
+[[ $(nix registry list | wc -l) == 37 ]]
+# sanity check, contains the important ones
+nix registry list | grep '^global flake:nixpkgs'
+nix registry list | grep '^global flake:home-manager'
+
+
+# the online flake registry should still work, but it is deprecated.
+set -m
+# port 0: auto pick a free port, unbufferred output
+python3 -u -m http.server 0 --bind 127.0.0.1 > server.out &
+# wait for the http server to admit it is working
+while ! grep -qP 'port \d+' server.out ; do
+  echo 'waiting for python http' >&2
+  sleep 0.2
+done
+
+port=$(awk 'match($0,/port ([[:digit:]]+)/, ary) { print ary[1] }' server.out)
+
+sed -i '/flake-registry/d' "$NIX_CONF_DIR/nix.conf"
+echo "flake-registry = http://127.0.0.1:$port/flake-registry.json" >> "$NIX_CONF_DIR/nix.conf"
+cat <<EOF > flake-registry.json
+{
+    "flakes": [
+        {
+        "from": {
+            "type": "indirect",
+            "id": "nixpkgs"
+        },
+        "to": {
+            "type": "github",
+            "owner": "NixOS",
+            "repo": "nixpkgs"
+        }
+        },
+        {
+        "from": {
+            "type": "indirect",
+            "id": "private-flake"
+        },
+        "to": {
+            "type": "github",
+            "owner": "fancy-enterprise",
+            "repo": "private-flake"
+        }
+        }
+    ],
+    "version": 2
+}
+EOF
+
+[[ $(nix registry list | wc -l) == 2 ]]
+nix registry list | grep '^global flake:nixpkgs'
+nix registry list | grep '^global flake:private-flake'
+
+# make sure we have a warning:
+nix registry list 2>&1 | grep "config option flake-registry referring to a URL is deprecated and will be removed"
+
+kill %1
diff --git a/tests/functional/meson.build b/tests/functional/meson.build
index 1e68cfe8c..a13dee001 100644
--- a/tests/functional/meson.build
+++ b/tests/functional/meson.build
@@ -69,6 +69,7 @@ functional_tests_scripts = [
   'flakes/unlocked-override.sh',
   'flakes/absolute-paths.sh',
   'flakes/build-paths.sh',
+  'flakes/flake-registry.sh',
   'flakes/flake-in-submodule.sh',
   'gc.sh',
   'nix-collect-garbage-d.sh',
diff --git a/tests/nixos/github-flakes.nix b/tests/nixos/github-flakes.nix
index 1954208b9..e3437c5e8 100644
--- a/tests/nixos/github-flakes.nix
+++ b/tests/nixos/github-flakes.nix
@@ -146,6 +146,8 @@ in
           virtualisation.additionalPaths = [ pkgs.hello pkgs.fuse ];
           virtualisation.memorySize = 4096;
           nix.settings.substituters = lib.mkForce [ ];
+          # note: URL flake-registries are currently deprecated.
+          nix.settings.flake-registry = "https://channels.nixos.org/flake-registry.json";
           nix.extraOptions = "experimental-features = nix-command flakes";
           networking.hosts.${(builtins.head nodes.github.networking.interfaces.eth1.ipv4.addresses).address} =
             [ "channels.nixos.org" "api.github.com" "github.com" ];